Haydee Chávez

Cytotoxic triterpenoids from Maytenus retusa.

Seven new triterpenoids (1-7) and 36 known compounds were isolated from the root bark of Maytenus retusa. Their structures were determined by 1D and 2D spectroscopic studies. Several compounds were evaluated for their cytotoxicity against the human tumor cell lines HL-60 and MCF-7. Some of them were cytotoxic, with IC(50) values ranging between 0.2 and 4.7 μM.

FIRST EXAMPLES OF DAMMARANE TRITERPENES ISOLATED FROM CELASTRACEAE

Abstract Eight new dammarane triterpenes were isolated from Maytenus Macrocarpa . Their structures were determined by means of 1 H and 13 C NMR spectroscopic studies, including 1 H- 13 C heteronuclear correlation (HETCOR), long range correlation with inverse detection (HMBC), and chemical evidence. This is the first time that dammarane triterpenes have been isolated from Celastraceae.

Macrocarpins A-D, new cytotoxic nor-triterpenes from Maytenus macrocarpa

Macrocarpins A (1), B (2), C (3) and D (4), four new nor-triterpenes, have been isolated from the roots of Maytenus macrocarpa. The structures were established by spectroscopic examinations. Natural compounds 1, 2, 4 and the acetyl derivative 1a are cytotoxic against four tumoral cell lines with IC50 values ranging between 0.4 and 5.2 microM.

Structure of new bioactive triterpenes related to 22-β-hydroxy-tingenone

Abstract Nine new triterpenes were isolated from Maytenus amazonica. Their structures were determined by means of 1H and 13C NMR spectroscopic studies, including 1H-13C heteronuclear correlation (HETCOR), and long range correlation with inverse detection (HMBC). Some of them showed cytotoxic activity.

New phenolic and quinone-methide triterpenes from Maytenus amazonica.

The new nortriterpene methylene quinones amazoquinone (1) and (7S, 8S)-7-hydroxy-7,8-dihydro-tingenone (2), and the new norphenolic triterpenes 7,8-dihydro-6-oxo-tingenol (3), 23-nor-6-oxo-tingenol (4), and 23-oxo-iso-tingenone (5) were isolated from Maytenus amazonica. Their structures were elucidated by spectroscopic methods. Compounds 1, 2, 3, and 5 showed low antitumor activity against four cancer cell lines.

Triterpenoids and a lignan from the aerial parts of Maytenus apurimacensis.

Five new triterpenes (1-5) and one new lignan (6) were isolated from the aerial parts of Maytenus apurimacensis. Their structures were determined on the basis of spectroscopic studies, including homonuclear and heteronuclear correlation NMR experiments (COSY, ROESY, HSQC, and HMBC).